Motion takeup device



May 19, 1970 H. B. CHAMBERS 3,51

MOTION TAKEUP DEVICE l 2 Sheets-Sheet 1 Filed Sept. 21, 1967 INVEN TOR. Y 76. 6%

ATTORNEY United States Patent 3,512,657 MOTION TAKEUlP DEVICE Henry B. Chambers, Santa Barbara, Calif., assignor to Hydranautics, Santa Barbara, Calif., a corporation of California Filed Sept. 21, 1967, Ser. No. 673,246 Int. Cl. B65g 67/58 US. Cl. 214-1 Claims ABSTRACT OF THE DISCLOSURE The mechanism is normally contracted or telescoped and extends when manually pulled. The amount of extension is at least equal to the height of a wave from crest t0 valley. In this fashion the mechanism can be extended to accommodate the motion, due to waves, of a boat or barge being unloaded. Once the manual pull is released, the mechanism contracts when the upward motion of the load connected to it permits, and has a check device that then functions to prevent extension when under load. The mechanism permits hook-up of the load when the load is moving downwardly on a wave and permits hoisting of the load without jerking when the load is moving upwardly on a wave, or when the load reaches the crest of a wave.

DESCRIPTION My invention relates to marine hoisting mechanisms and has particular reference to a motion takeup mechanism for lifting loads when the lifting rope and the loaded boat are moving relative to each other in a vertical direction.

The lifting of cargo or other loads from boats and ships is difficult when wave motion cause a relative vertical movement between the crane or other lifting mechanim, and the boat or ship. The same problem arises when a floating crane lifts loads from a stationary dock and the problem arises also in lifting loads from one boat or ship to another.

A heavy load moving up and down with the wave motion acquires considerable acceleration. As a load moves downwardly, it has momentum added to its normal weight and if lifted from the boat at this instant in time, the stress placed on the lifting mechanim is multiplied. Conversely, if a load is moving upwardly with a wave, its upward momentum decreases its apparent weight, and if the load is lifted during this period in time, the initial stress on the lifting mechanism is less than the weight would indicate. These momentum loads are expressed in terms of gravity as either negative G loading or positive G loading.

Another hazard in lifting loads from boats is the possibility of damage to the boat or load if lifting is started and the wave action moves the boat and load together. If the lifting action is less rapid than the wave action, the load and boat strike each other, damaging one or both. Since many lifting mechanisms have a lifting speed less rapid than the wave action, considerable skill is necessary to avoid these collisions.

The present invention provides a hoisting device that has a motion takeup action that makes it possible to regularly lift a load from a boat at the crest of the wave. The hoisting device of the invention is extensible by a small manual pull, but the takeup action is automatic once the manual pull is released. This permits extension of the load lifting device while the boat and its load are traveling downwardly and permits the application of a lifting force to a load at any time the load is moving upwardly. If the wave lifts the load faster than the hoist, the motion takeup mechanism mechanically shortens as fast as the wave lifts the load. This results in the load auto- 3,512,657 Patented May 19, 1970 ice matically being lifted at the crest of the wave. This is the instant of zero G loading and also the instant that insures against damage by the boat striking the load.

Various objects, features and advantages of the invention will be apparent in the following specification, considered together with the drawings forming an integral part of this disclosure in which:

FIGS. 1 through 4 are schematic views in elevation illustrating steps in the hoisting of a load to which a device embodying the invention is connected.

FIG. 1 shows a barge near the crest of a wave with the takeup device at maximum contraction.

FIG. 2 shows the barge moving downwardly on a wave.

FIG. 3 shows the barge at the bottom of a wave or at the wave valley with the takeup device at maximum extension.

FIG. 4 shows the barge at the crest of a wave with the load being lifted from it.

FIG. 5 is an elevation view of a schematic mechanical device embodying the invention.

FIG. 6 is a schematic hydraulic device embodying the invention, wherein air is used as a resilient force to apply pressure to the hydraulic system.

FIG. 7 is an elevation view in full section of a pneumatic hydraulic device working on the principles of schematic FIG. 6 embodying the invention.

FIG. 8 is a bottom view of FIG. 7.

FIG. 9 is a fragmentary sectional view of a portion of the sidewalls of a device similar to that of FIG. 7, but having an additional telescoping member.

Referring to FIGS. 1 through 4, there is illustrated a takeup device 10 embodying the invention, and for purposes of clarity the device or mechanism 10 is referred to herein as takeup. The takeup consists of an outer housing 11 in which a lower slide member 12 is adapted to telescope. The takeup is designed to be disposed between a hoisting rope 13 and a cargo hook 14. Connected to the lower end of the hoisting rope 13 is a hook 16, fitting in an eye 17 on the upper end of the housing 11. Disposed on the lower end of the slide 12 is an eye 17 to which is connected a short length of rope 18, which in turn supports the car-go hook 14. Pivoted to the lower end of the slide 12 is a pair of control levers 19 actuated by a rope 21 which is adapted to be manually grasped.

The cargo to be lifted is supported on a body of water 22, subject to waves having a crest 23 and a trough 24. Floating on this water 22 is a barge 26 supporting a cargo 27 which is lashed about with a hoisting net 28, terminating in an eye 29. A pair of workmen 31 and 32 are also supported by the barge 26.

* OPERATION OF FIGS. 1 TO 4 The operation of the device illustrated in FIGS. 1 through 4 is initiated by a crane (not shown) lowering the hoisting rope 13 with the takeup 10 attached thereto and having the cargo hook 14 attached to the lower end of the takeup 10. The crane operator lowers the assembly until the workman 32 can grasp the lower end of the control rope 21, whereupon he gives the rope 21 a manual pull which causes the levers 19 to rotate from the position of FIG. 1 to the position of FIG. 2. This manual pull by the workman 32 not only trips the mechanism of the takeup 10 to permit it to extend, but also is the force by which the takeup is caused to be extended. The slide 12 thereupon extends until the cargo hook 14 is opposite the cargo net eye 29, whereupon the workman 31 connects the hook into the eye 29.

While the takeup 10 can be connected to the cargo 27 at any time, whether the cargo is being lifted by the wave 23 or being lowered by the wave, the most eflicient operation occurs when the barge 26 is traveling downwardly. This is illustrated in FIGS. 1 through 3, wherein the cargo is at the crest of the wave in FIG. 1, is starting to lower in FIG. 2, and is at the bottom or valley of the wave in FIG. 3. The operator 32, by continuing to pull on the control rope 21, causes the slide 12 to be extended, as previously mentioned, until it is opposite the cargo eye 29. Accordingly, as shown in FIG. 3, the slide 12 is at its maximum extension, and the hook-up has been completed. However, to enable this to happen, the operator 32 has maintained his pull upon the slide 12 to obtain this extension as the wave is moving the cargo 27 downwardly. When the hook-up is completed, and the cargo is at the bottom 24 of the wave, as shown in FIG. 3, or the wave is starting to lift the cargo 27, the operator 32 releases the control rope 21, and at the same time gives a manual signal to the crane operator to lift the hoisting cable 13. In actual practice, considerable time is required to complete the operation and several waves will pass before it is completed. The rigger 32 merely holds steady on the rope 21, and the hook 14 moves up and down with the wave action at the desired distance above the load 27.

The velocity of hoisting the cable 13 in most cranes is usually less than the speed of lifting of the wave. Accordingly, as the wave lifts the barge 26 upwardly, the takeup 10 performs its takeup function of shortening, and this is shown by comparing FIGS. 3 and 4. The release of the control rope 21 causes the levers 19 to rotate to their rest position, which restores the takeup to its normal checking function (by mechanism to be described later) which allows the takeup 10 to shorten, but prevents it from lengthening even under severe loads. The takeup 10 continues to shorten or telescope until the barge 26 is at the crest of the wave, as shown in FIG. 4, whereupon the upward movement of the hoisting cable or rope 13, lifts the cargo 27. This occurs at the crest 23 of the wave, where the upward movement of the cargo 27 comes to rest and before it can start downwardly. Accordingly, there is no possibility of G loading of the cargo, and the lift is smoothly accomplished without any jerking of the cargo. In this connection, the internal shortening force of the takeup 10 is sufficient to tighten the cargo net 28 so that there is no slack in the system where the lifting actually occurs.

DESCRIPTION OF OTHER FIGURES Referring to FIG. 5, there is illustrated schematically a mechanical device 33 for accomplishing the action just described for the takeup 10 of FIGS. 1 through 4. An outer housing 34 has the usual lifting eye 36 on the top end, and has a two part slide at the lower end, consisting of a lifting slide 37 and a pivoted slide 38, pivoted to 37 by a plurality of links 39. A weak spring 41 is connected to the upper end of the lifting slide 37 and to the housing 34. Another spring 42 is connected between the two slide members 37 and 38, urging the pivoted slide 38 upwardly with respect to the slide 37. Connected to the bottom end of slides 37 and 38 is a lever 43 having a control rope 44 secured to its outer end. The pivoted slide member 38 rubs against a brake shoe 46, and the slide member 37 rubs against a lubricated guide 47. Connected to the bottom of the lifting slide 37 is a rope 48 terminating in a cargo hook 49.

The operation of the device of FIG. is similar to the device of FIGS. 1 through 4. An operator pulls downwardly on the rope 44, moving the slide 38 downwardly, removing its contact with the brake shoe 46. Continued pulling on the lever 44 pulls both slides downwardly against the tension of spring 41 until the cargo hook 47 can be connected to the cargo to be hoisted. If the cargo is moving downwardly on a wave, both slides 37 and 38 move downwardly together against the tension of spring 41. The spring 41 is light enough so that a manual pull on the rope 44 can extend it. When the hook-up is completed, and the wave starts to lift the cargo, the operator releases the rope 44, whereupon spring 42 causes it to rotate counterclockwise, and bring the slide 38 in contact with the brake shoe 46. If the wave lifts the cargo faster than a hoist can lift the takeup, the spring 41 contracts, lifting both slides 37 and 38 together. If, however, the crest of the wave is reached, or the cargo starts to move downwardly, then the pull of the hoisting cable (not shown) causes the brake slide 38 to be wedged tightly against the brake shoe 46, preventing downward movement of either slide 37 or 38. The cargo then is lifted by continued lifting of the hoist rope connected to the eye 36.

Referring to FIG. 6, there is a schematic diagram of a pneumatic-hydraulic system for accomplishing the same function as the device of FIG. 5. A motor cylinder 50 has an open hole or breather 51 at the top end thereof and a lifting eye 55. A motor piston 52 reciprocates therein and has a piston rod 53 connected to its lower end which extends through a seal '54 in the bottom end of the motor cylinder 50. A hydraulic conduit 56 is connected to the lower end of the motor cylinder 50 and has two branches 57 and 58 which connect to a single conduit 59, connected through a restriction 61 to the bottom end of an accumulator 62. The upper end of the accumulator 62 is charged with air through a valve fitting 63 and a movable piston diaphragm 64 separates the air or other gas from liquid contained in the bottom part of the accumulator 62.

The operation of the takeup of FIG. 6 is controlled by a valve in the branch 57. Accordingly, a poppet valve 66 is disposed in a valve chamber 67 and is manually lifted against pressure by a manual lever 68. This lever may have a control rope connected to it such as the control rope 21 FIGS. 1 through 4. In the other branch 58 a relief valve 69 may be located which permits fluid to flow from the motor cylinder 50 to the accumulator 62 when the pressures exceed a predetermined safe pressure. This avoids breakage of the apparatus under unusual conditions.

In operation, a cargo hook (not shown) is connected to the bottom of the piston rod 53. When it is desired to extend the piston rod 53, a manual pull is exerted on the lever 68 and simultaneously on the piston rod 53. This permits fluid to flow from the motor cylinder 50 below the piston '52 out through the pipe 56 past the now open poppet 66, and through the conduit 59 into the bottom of accumulator 62. This causes the diaphragm 64 to move upwardly against the pressure of the air in the top part of the accumulator. This air pressure is selected, however, at an amount such that a manual pull on the piston rod 53 can overcome this air pressure and allow the diaphragm 64 to move upwardly. When the cargo hook (not shown) is connected, and it is desired that the device contract as the upwardly moving load permits, the operator releases his pull on lever 68, and the poppet valve 66 thereupon seats. Since the downward pull on the piston rod 53 is now released also, the air in accumulator 62 forces the liquid past the restriction 61 into the conduit 59 into the branch 57, lifting the poppet 66, whereupon it passes through the conduit 56 into the bottom of the motor cylinder 50, lifting piston 52. If a force is now applied to the bottom of the piston rod 53, as when a cargo is being lifted, the hydraulic pressure seats the valve 66, and the piston rod maintains its position as of that moment. A hoisting rope connected to the eye on the top of the motor cylinder 50 will now lift the entire mechanism upwardly, together with the load attached to the bottom of the piston rod 53.

Illustrated in FIGS. 7 and 8 is a commercial embodiment of the mechanism shown schematically in FIG. 6. An outer tubular member 50 acts as a motor cylinder wall and has its upper end closed by a threaded-in plate 71, which has a breather opening 51 therein through which the air can pass after filtering by a breather filter 72. Projecting from the top of the closure plate 71 is a lifting eye 55 adapted to be connected to a hoisting cable, such as the hoisting rope 13 in FIGS. 1 through 4.

Projecting from the bottom end of the cylinder motor 50 is a tubular piston rod 53, having a bottom closure 73 threaded thereon and a top partition member 74 threaded thereon. The partition member 74 is cup shaped, having an outer rim 52 that forms a piston between the tubular piston rod 53 and the interior of the motor cylinder 50. A plate 60 is threaded into the top of the cup member 74. Threaded to the bottom of the cylinder 50 is a tubular closure 75 which guides the tubular piston rod 53 and which defines a motor space 76.

The bottom part of the tubular piston rod 53 is filled with air by means of a valve 63, and this air is separated from hydraulic fluid by means of a diaphragm 64 which reciprocates up and down inside of the tubular piston rod 53. The partition member 74 is centrally bore at 77 to communicate the space above the diaphragm 64 with the interior of the cup shaped partition member 74. Formed in the sidewalls of the cup shaped partition member 74 are apertures 78 which communicate the interior of that cup with the work space 76.

Hydraulic fluid is trapped in the work space 76 of the motor by means of a poppet valve 66 positioned at the top of the bore 77. This poppet 66 may be manually opened or lifted by means of a stem 79 connected to its bottom end which passes through the diaphragm 64 and through the bottom closure 73 to project outwardly from that bottom closure. Fitted around the projecting lower end is a compression spring 81 which abuts against a collar 82 on the bottom end of the stem 79. Projecting from the bottom closure 73 is a double eye fitting 83 between which pivot rods 84 extend to pivot two pairs of levers 68 which actuate the poppet valve 66. A rod 86 passes through the collar 82 and is engaged by elongated slots 87 on the inner ends of the levers 86, so that when the levers are pivoted, they lift the collar 82 and in turn lift the poppet valve 66.

OPERATION OF FIGS. 7 AND 8 The takeup of FIGS. 7 and 8 is made operative by charging the device with air pressure through the fitting 63 on the lower end, which causes the diaphragm 64 to rise to exert pressure against the hydraulic liquid that fills the interior of the device. This hydraulic liquid lifts poppet valve 66 against the compression of spring 81 on the bottom end of its stem 79, and the liquid flows through the ports 78 into the work chamber 76. This exerts a pressure between the lower bushing 75 and the upper piston 52, which define the working space 76. This causes the entire hollow piston rod 53 to move upwardly in FIG. 7.

When it is desired to extend the takeup, the outer ends of the levers 68 are moved downwardly. This lifts the poppet valve 66 permitting fluid to flow from the chamber above it into the chamber below it against the compression of the air beneath the diaphragm 64. Accordingly, when a mechanical pull is exerted on the outer ends of the lever 68, the entire tubular piston rod 53 is moved downwardly when the pull exceeds the compression of the air. When a cargo is connected to the bottom end of the eyes 83, and it is desired to allow the device to contract, the operator releases the manual pull on the outer ends of the levers 68, and the spring 81 thereupon seats the poppet 66. The air below the diaphragm 64 then pushes the liquid past the poppet 66 through the apertures 78 and into the work space 76, which pushes the hollow piston rod 53 upwardly.

If now a heavy force is applied to the eyes 83 on the bottom of the device, the liquid in the work chambers 76 will attempt to move through the apertures 78 and into the space below the poppet valve 66. This instantly seats the poppet valve 66, and the liquid is trapped, preventing any extension of the device. If the entire device is then lifted by a suitable crane, the cargo attached to its lower end is lifted also. If, by any chance, the load being lifted exceeds the mechanical strength of the entire device, a relief valve 69 in the partition 74 will open to permit fluid to bypass the poppet valve 66 to thereby prevent damage to the entire device;

It will be recognized that the poppet valve 66 is in fact a check valve that locks up the device from extending. The manual mechanism for unseating this check valve 66 is properly referred to as a manual check release. The resilient operation of the air in the accumulator is properly referred to as a biasing action, and a mechanical or pneumatic spring for this purpose can be referred to as a biaser. It will be appreciated that if the apertures 78 are made small enough there will be restriction of flow and these alone could result in a slowly releasing locking action. These holes 78 regulate the rate of extension and contraction of the takeup. Various lifting mechanism can be used, and various devices can be attached to the lower end, such as life boats and other non-cargo items. For this reason the use of the words lifting rope and lifting hook as used in the claims, are suggestive only and not limiting.

Illustrated in FIG. 9 is a fragmentary showing of three interior telescoping members. An inner piston head 52a has an aperture 78a in its sidewall to pass liquid to a work space 76a. This piston head 52m reciprocates within another tube a, having a piston head 91a and an aperture 92a communicating with a work space 93a, defined between it and an outer tube 50a. The two work spaces 93a and 76a communicate with each other, and the relative size of the cross section of the two work spaces will determine which of the two piston heads 52a and 91a will move up first when liquid under pressure is applied to their respective work spaces. By means of such construction, as shown in FIG. 9, an extending slide can be greater in length than the housing within which it fits.

It will be appreciated by those skilled in the art that various modifications may be made in the device. For example, a downward pull on the levers could supply fluid under pressure to the top of the piston 52, and in this case, the breather 72 would be substituted with a pressure vessel with suitable means of exhausting the used fluid. Also, the hydraulic system could be ditferently arranged, with exterior accumulators. Springs could be used instead of air, as the resilient force. Further, in the device of FIG. 7, air could be stored at the top and liquid at the bottom, making unnecessary a diaphragm. Rotary as well as linear devices can be used.

I claim:

1. A motion takeup for connecting between a lifting rope and a lifting hook comprising,

(a) an outer tube with one of said rope or hook adapted to be connected to one end,

(b) an inner tube telescoping with the outer tubes at the other end of the outer tube and having an outer end adapted to be connected to the other of said rope or hook,

(c) closures at both ends of the inner tube to define a gas chamber at one end and a liquid chamber at the other,

((1) a piston formed on the inner tube between the inner and outer tubes to define a working space,

(e) a passage connecting the working space with liquid chamber,

(f) a partition in the inner tube between the passage and the air chamber,

(g) a check valve in the partition permitting liquid flow only in the direction away from the air chamber, so that the tubes are normally telescoped and preventing extension of the tubes under load,

(h) and a release for said check valve to permit selected extension of the tubes when the force of the air chamber is overcome.

2. A motion takeup as set forth in claim 1 wherein a relief valve is also disposed in the partition to allow extension of the tubes in the event of an overload.

3. A motion takeup as set forth in claim 1 wherein a diaphragm is disposed in the inner tube to separate the gas chamber from the liquid chamber.

7 4. A motion takeup apparatus for connecting between a lifting rope and a lifting hook comprising:

(a) a first housing adaptable for connecting with one of said lifting rope or lifting hook;

(b) a telescoping slide slidingly connected to said first housing and adaptable for engaging the other of said lifting rope or lifting hook to its outer end;

() a resilient biaser interconnecting said first h0using and said telescoping slide to move the slide toward the housing and normally holding it telescoped with said first housing;

((1) a second housing defining a chamber containing an incompressible fluid;

(e) an automatic check valve connected between said first and second housing in communication with said chamber to stop fluid flow from said chamber; and

(f) manual means coupled to said check valve for opening said check valve to selectively permit reduction in volume of said chamber so that said slide can extend from said first housing.

5. A motion takeup apparatus for connecting between a lifting rope and a lifting hook comprising:

(a) a housing defining an outer tube adaptable for connecting with one of said lifting rope or lifting hook;

(b) a telescoping slide defining an inner tube connected to said housing and adaptable for engaging the other of said lifting rope or lifting hook wherein said housing and slide telescope with each other,

from extending from said housing but permitting telescoping movement; and (d) a manual release coupled to said check lock to release the lock and permit extension of said slide.

References Cited UNITED STATES PATENTS 2,045,533 6/1936 Smaltz. 2,946,466 7/1960 Weiner 214-14 FOREIGN PATENTS 795,280 1/1936 France.

GERALD M. FORLENZA, Primary Examiner F. E. WERNER, Assistant Examiner US. Cl. X.R. 

